Messages in this thread | | | Subject | Re: [PATCH] arm64: Clear the stack | From | Laura Abbott <> | Date | Fri, 29 Jun 2018 13:22:58 -0700 |
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On 06/29/2018 01:19 PM, Kees Cook wrote: > On Fri, Jun 29, 2018 at 12:05 PM, Laura Abbott <labbott@redhat.com> wrote: >> Implementation of stackleak based heavily on the x86 version >> >> Signed-off-by: Laura Abbott <labbott@redhat.com> >> [...] >> +#define current_top_of_stack() (task_stack_page(current) + THREAD_SIZE) >> +#define on_thread_stack() (on_task_stack(current, current_stack_pointer)) > > nit on types here. I get some warnings: > > kernel/stackleak.c:55:12: warning: assignment makes integer from > pointer without a cast [-Wint-conversion] > boundary = current_top_of_stack(); > ^ > kernel/stackleak.c:65:24: warning: assignment makes integer from > pointer without a cast [-Wint-conversion] > current->lowest_stack = current_top_of_stack() - THREAD_SIZE / 64; > ^ > > So I think this needs to be: > > +#define current_top_of_stack() ((unsigned long)task_stack_page(current) + \ > + THREAD_SIZE) >
Argh, missed that in an amend, can fix for next version if there are no other objections to this approach.
>> diff --git a/scripts/Makefile.gcc-plugins b/scripts/Makefile.gcc-plugins >> index a535742a1c06..972ce4ca7f6a 100644 >> --- a/scripts/Makefile.gcc-plugins >> +++ b/scripts/Makefile.gcc-plugins >> @@ -37,11 +37,14 @@ ifdef CONFIG_GCC_PLUGINS >> >> gcc-plugin-$(CONFIG_GCC_PLUGIN_STACKLEAK) += stackleak_plugin.so >> gcc-plugin-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK) += -DSTACKLEAK_PLUGIN -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_STACKLEAK_TRACK_MIN_SIZE) >> + ifdef CONFIG_GCC_PLUGIN_STACKLEAK >> + DISABLE_STACKLEAK_PLUGIN += -fplugin-arg-stackleak_plugin-disable >> + endif >> >> GCC_PLUGINS_CFLAGS := $(strip $(addprefix -fplugin=$(objtree)/scripts/gcc-plugins/, $(gcc-plugin-y)) $(gcc-plugin-cflags-y)) >> >> export PLUGINCC GCC_PLUGINS_CFLAGS GCC_PLUGIN GCC_PLUGIN_SUBDIR >> - export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN >> + export SANCOV_PLUGIN DISABLE_LATENT_ENTROPY_PLUGIN DISABLE_STACKLEAK_PLUGIN >> >> ifneq ($(PLUGINCC),) >> # SANCOV_PLUGIN can be only in CFLAGS_KCOV because avoid duplication. > > If there is a v14, I think this hunk should be taken there, since it's > part of the common code. > > Otherwise, this works for me and passes the lkdtm tests. > > -Kees >
Thanks, Laura
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